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From: Ram Pai <linuxram@us.ibm.com>
To: linux-pci@vger.kernel.org
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	Yinghai Lu <yinghai@kernel.org>,
	linuxram@us.ibm.com
Subject: [RFC PATCH v3 ]pci: pci resource iterator
Date: Thu, 23 Aug 2012 13:09:58 +0800	[thread overview]
Message-ID: <20120823050958.GB2332@ram-ThinkPad-T61> (raw)
In-Reply-To: <CAE9FiQXyVB5AGGOd+a-SatL+dEo7Nvx=zPswtZ1QLk5QSLMm4Q@mail.gmail.com>

    PCI: pci resource iterator
    
    Currently pci_dev structure holds an array of 17 PCI resources; six
    base BARs, one ROM BAR, four BRIDGE BARs, six sriov BARs.  This is
    wasteful. A bridge device just needs the 4 bridge resources. A
    non-bridge device just needs the six base resources and one ROM
    resource. The sriov resources are needed only if the device has
    SRIOV capability.
    
    The pci_dev structure needs to be re-organized to avoid unnecessary
    bloating.  However too much code outside the pci-bus driver, assumes
    the internal details of the pci_dev structure, thus making it hard
    to re-organize the datastructure.
    
    As a first step this patch provides generic methods to access the
    resource structure of the pci_dev.
    
    Next step, change the code in all the drivers that access the
    resource structure to use the new iterator.
    
    Finally we can re-organize the resource structure in the pci_dev
    structure and correspondingly update the methods.
    
    This patch is compile tested only.
    
    Changelog v2:
            Consolidated iterator interface as per Bjorn's suggestion.
    
    Changelog v3:
    	ability to get index of the returned resource. Suggested by Yinghai.
    	Incorporates Yinghai's code snippets.
    
<TODO get Yinghai's SOB>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>

diff --git a/include/linux/pci.h b/include/linux/pci.h
index e444f5b..7101da2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1351,6 +1351,48 @@ static inline int pci_domain_nr(struct pci_bus *bus)
 	 (pci_resource_end((dev), (bar)) -		\
 	  pci_resource_start((dev), (bar)) + 1))
 
+#define PCI_STD_RES		(1<<0)
+#define PCI_ROM_RES		(1<<1)
+#define PCI_BRIDGE_RES		(1<<2)
+#define PCI_IOV_RES		(1<<3)
+#define PCI_ALL_RES	(PCI_STD_RES|PCI_ROM_RES|PCI_BRIDGE_RES|PCI_IOV_RES)
+#define PCI_NOSTD_RES		(PCI_ALL_RES & ~PCI_STD_RES)
+#define PCI_NOIOV_RES		(PCI_ALL_RES & ~PCI_IOV_RES)
+#define PCI_NOROM_RES		(PCI_ALL_RES & ~PCI_ROM_RES)
+#define PCI_NOBRIDGE_RES	(PCI_ALL_RES & ~PCI_BRIDGE_RES)
+#define PCI_STD_ROM_RES		(PCI_STD_RES | PCI_ROM_RES)
+#define PCI_STD_IOV_RES		(PCI_STD_RES | PCI_IOV_RES)
+#define PCI_STD_ROM_IOV_RES	(PCI_NOBRIDGE_RES)
+
+static inline struct resource *pci_dev_resource_n(struct pci_dev *dev, int n)
+{
+	if (n >= 0 && n < PCI_NUM_RESOURCES)
+		return &dev->resource[n];
+
+	return NULL;
+}
+
+static inline int pci_next_resource_idx(int i, int flag)
+{
+	while (++i < PCI_NUM_RESOURCES) {
+		if ((i >= 0 && i < PCI_ROM_RESOURCE && (flag & PCI_STD_RES)) ||
+		    (i == PCI_ROM_RESOURCE && (flag & PCI_ROM_RES)) ||
+#ifdef CONFIG_PCI_IOV
+		    (i <= PCI_IOV_RESOURCE_END && (flag & PCI_IOV_RES)) ||
+#endif
+		    (i <= PCI_BRIDGE_RESOURCE_END && (flag & PCI_BRIDGE_RES)))
+			return i;
+	}
+	return -1;
+}
+
+#define for_each_pci_resource(dev, res, flag) \
+	for (i = pci_next_resource_idx(-1, flag), \
+			res = pci_dev_resource_n(dev, i); \
+	     res; \
+	     i = pci_next_resource_idx(i, flag), \
+			res = pci_dev_resource_n(dev, i))
+
 /* Similar to the helpers above, these manipulate per-pci_dev
  * driver-specific data.  They are really just a wrapper around
  * the generic device structure functions of these calls.


  reply	other threads:[~2012-08-23  5:10 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-18  5:03 [RFC PATCH] methods to access resources of a struct pci_dev Ram Pai
2012-06-18 18:30 ` Yinghai Lu
2012-06-19  1:46   ` Ram Pai
2012-06-19  2:57     ` Yinghai Lu
2012-08-15 21:25   ` Bjorn Helgaas
2012-08-16  3:26     ` Ram Pai
2012-08-16  4:11       ` Yinghai Lu
2012-08-16  4:41         ` Ram Pai
2012-08-21 15:13           ` [RFC PATCH v2 ]pci: pci resource iterator Ram Pai
2012-08-21 23:22             ` Yinghai Lu
2012-08-22 10:15               ` Ram Pai
2012-08-22 17:31                 ` Yinghai Lu
2012-08-22 17:35                   ` Yinghai Lu
2012-08-23  0:28                     ` Yinghai Lu
2012-08-23  5:09                       ` Ram Pai [this message]
2012-08-23 19:30                         ` [RFC PATCH v3 " Yinghai Lu
2012-08-27  7:33                           ` Ram Pai
2012-09-03  8:07                             ` Yinghai Lu
2012-09-03  9:08                               ` Ram Pai
2012-09-03 18:20                                 ` Yinghai Lu
2012-09-04  3:27                                   ` Ram Pai
2012-09-18  0:03                                     ` Yinghai Lu
2012-09-21  6:18                                       ` Ram Pai
2012-09-21  6:27                                         ` Yinghai Lu

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